The last Days i made some experiments to cut Objects and Bitmaps with generated Grids in Inkscape.
This are the two results :
You can use this pictures by Creative Commons Attribution 3.0 Unported License
The way is simple but much work:
Import an Bitmap and convert it to a Pattern. Then use Effects > Render > Grid.
Now mark both (Bitmap and Grid) and cut it with Path > Division.
Now you have to arrange the squares manually with your Mouse or Tablett-Pen.
If you have an easy Objekt with just one color, then you can open the Align Dialog and try this Button:
What do you think about this kind of technique ?